CircularRingBuffer.c

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>

typedef struct cache_t {
	int timestamp;
	float value;
} cache_t;

typedef struct cache_buffer_t {
	cache_t *buff;
	int start;
	int end;
	int size;
	int count;
} cache_buffer_t;

cache_buffer_t* init_buffer(int size);
void push_to_buffer(cache_buffer_t *cb, cache_t cache);
void print_buffer(cache_buffer_t *cb);

int main() {
	printf("Hello World\n");
	cache_buffer_t *cb = init_buffer(3);

	cache_t data1;
	data1.timestamp = 100;
	data1.value = 10.20;

	cache_t data2;
	data2.timestamp = 200;
	data2.value = 20.30;

	cache_t data3;
	data3.timestamp = 300;
	data3.value = 30.40;

	cache_t data4;
	data4.timestamp = 400;
	data4.value = 40.50;

	cache_t data5;
	data5.timestamp = 500;
	data5.value = 500.60;

	cache_t data6;
	data6.timestamp = 600;
	data6.value = 60.50;

	push_to_buffer(cb, data1);
	push_to_buffer(cb, data2);
	push_to_buffer(cb, data3);
	push_to_buffer(cb, data4);
	push_to_buffer(cb, data5);
	push_to_buffer(cb, data6);

	printf("Add success\n");
	print_buffer(cb);
	return 0;
}

cache_buffer_t* init_buffer(int size) {
	cache_buffer_t *cb = (cache_buffer_t*) malloc(sizeof(cache_buffer_t));
	memset(cb, 0, sizeof(cache_buffer_t));
	cb->size = size;
	cb->buff = (cache_t*) malloc(sizeof(cache_t) * size);
	return cb;
}

void push_to_buffer(cache_buffer_t *cb, cache_t cache) {
	int end = cb->end;
	if (cb->count && (end % cb->size) == cb->start) {
		printf("Overflow Elem[%d] %d lost\n", cb->start,
				cb->buff[cb->start].timestamp);
		cb->start = (cb->start + 1) % cb->size;
		cb->count--;
	}
	printf("Added Elem[%d] = %d\n", cb->end, cache.timestamp);
	cb->buff[cb->end] = cache;
	cb->end = (cb->end + 1) % cb->size;
	cb->count++;
}

void print_buffer(cache_buffer_t *cb) {
	int start = cb->start;
	int end = cb->end;
	int i, count = 0;
	for (i = start; count < cb->count; i = (i + 1) % cb->size) {
		printf("Elem[%d] Timestamp = %d\n", i, cb->buff[i].timestamp);
		printf("Elem[%d] Value = %f\n", i, cb->buff[i].value);
		count++;
		if (i == (end - 1)) {
			break;
		}
	}
}